The International Rugby Board has called for Stade Francais scrum-half Jerome Fillol to feel the full force of the law if found guilty of spitting at Bath's Peter Stringer during their Amlin Challenge Cup quarter-final clash on Saturday.

Stringer complained to referee Nigel Owens following the incident that occurred in the first half of the Premiership side's 36-20 defeat but he did not see it and therefore did not act with the tournament not one of those trialling the extended Television Match Official powers that allow input for incidents of suspected foul play.

However, TV replays appeared to confirm the worst with independent citing officer Eugene Ryan set to act as a result. "That's as low as you can probably go," Stringer said following the game. "When you are on the end of something like that you are rattled by it, but try not to dwell on it. It's out of my hands now."

Stringer has since received the support of IRB chief executive Brett Gosper who took to Twitter to call for firm action. He wrote: "Spitting on Stringer should be punished to the full extent of the law."

Spitting by Fillot on Stringer should be punished to the full extent of the law.#NotRugby

Under the IRB disciplinary code, the sanction for spitting ranges between four and at least 11 weeks, depending on the severity of the offence with the maximum ban being 52 weeks.

The incident soured the game that saw the French side book a final four clash against Top 14 rivals Perpignan later this month. Leinster will tackle defending champions Biarritz in the other semi-final having seen off the challenges of Wasps and Gloucester respectively.